1. Field of the Invention
The present invention relates to a method of treating a substrate having a film with high water repellency formed thereon, a computer storage medium and a substrate treatment apparatus.
2. Description of the Related Art
For example, in a photolithography process in manufacturing processes of a semiconductor device, for example, resist coating treatment for forming a resist film by applying a resist solution onto a semiconductor wafer (hereinafter, referred to as a “wafer”), exposure processing for exposing the resist film to a predetermined pattern, developing treatment for developing the exposed resist film and so on are sequentially performed, whereby a predetermined resist pattern is formed on the wafer.
Regarding the above-described developing treatment of the resist film, there is a widely known method of supplying a developing solution from a nozzle to the central portion of the wafer while the wafer after the exposure processing is being rotated to thereby spread the developing solution over the wafer by the centrifugal force to develop the resist film on the wafer. For performing such a developing treatment, it is necessary to spread the developing solution so that the developing solution extends over the entire surface of the wafer.
Incidentally, a material with high water repellency is sometimes used as the material of resist. In the case of using the resist material with high water repellency, the developing solution does not extend over the entire wafer surface when rotating the wafer because the developing solution is low in wettability with respect to a resist film, thereby often causing development defects such as poor resolution and opening failure at locations where development is not normally performed.
Therefore, for example, Patent Document 1 suggests a developing treatment method of executing the following first to third steps as a method of reducing the development defects when the resist with high water repellency is used. Namely, pure water as a surface treatment liquid is supplied to a central portion of the wafer to enhance the wettability of the developing solution with respect to the resist film in the first step, and then the wafer is rotated around the vertical axis to form a liquid film of the pure water on the wafer surface. Subsequently, in the second step, the developing solution is supplied to the central portion of the wafer while the wafer is being rotated after the liquid film is formed. In this second step, the developing solution extends also to the location to which the surface treatment liquid has not sufficiently extended, because the wafer surface is likely to get wet due to the pure water. By the first step and the second step, a so-called pre-wet treatment of wetting in advance the entire wafer surface with the pure water and the developing solution is performed to improve the wettability of the developing solution supplied to the wafer surface during the development. Thereafter, the developing solution is supplied to the wafer while the wafer is being rotated in the third step, whereby the supplied developing solution spreads while wetting the top of the developing solution supplied in the second step to thereby develop the resist.    Patent Document 1: Japanese Laid-open Patent Publication No. 2009-33053